Biogeochemical Cycle Cycles that involve living organisms (bio), geological processes (geo), and chemical processes (chemical).
Organisms Cannot Exist Without Matter All living things are made of the same matter as non-living things (carbon, hydrogen, nitrogen, phosphorus, oxygen). Organisms use matter to assemble & break down essential nutrients for life.
Without Organisms, Matter Can Only Exist in its Present Form Biological processes transform matter through metabolic reactions.
Water Cycle Where is water found? Surface of ponds, lakes, etc. Atmosphere (vapor) Within organisms
Nitrogen Cycle Where is nitrogen found? In the air as nitrogen gas (N 2 ) In the ground as nitrates (fertilizers) In organisms
Nitrogen Cycle How does nitrogen enter the biotic world? Nitrogen fixation (bacteria convert N 2 to a “fixed” form) Absorption & assimilation Heterotrophy (food chain) http://www.biology.ualberta.ca/facilities/multimedia/uploads/ecology/ncycle.swf
Nitrogen Cycle How does nitrogen returns to the environment? Decomposition Denitrification (bacteria) Ammonification (excreted waste)